Aristotle distinguishes between two intellectual virtues: sophia and phronesis. Sophia (usually translated "wisdom") is the ability to think well about the nature of the world, to discern why the world is the way it is (this is sometimes equated with science); sophia involves deliberation concerning universal truths. Phronesis is the capability to consider the mode of action in order to deliver change, especially to enhance the quality of life. Aristotle says that phronesis is not simply a skill, however, as it involves not only the ability to decide how to achieve a certain end, but also the ability to reflect upon and determine that end (this latter point is denied by some commentators, who contend that Aristotle considers the desired end, eudaimonia, to be given, such that phronesis is merely the ability to achieve that end).

According to Aristotle' theory on rhetoric phronesis is one of the three ethos deeds (from nowadays rhetorical definitions one of the three traditional ethos deeds whereas the others are respectively eunoia and arete).

Gaining phronesis requires maturation, in Aristotle's thought:

Whereas young people become accomplished in geometry and mathematics, and wise within these limits, prudent young people do not seem to be found. The reason is that prudence is concerned with particulars as well as universals, and particulars become known from experience, but a young person lacks experience, since some length of time is needed to produce it (Nichomachean Ethics 1142 a).

Phronesis is concerned with particulars, because it is concerned with how to act in particular situations. One can learn the principles of action, but applying them in the real world, in situations one could not have foreseen, requires experience of the world. For example, if one knows that one should be honest, one might act in certain situations in ways that cause pain and offense; knowing how to apply honesty in balance with other considerations and in specific contexts requires experience.

Aristotle holds that having phronesis is both necessary and sufficient for being virtuous; because phronesis is practical, it is impossible to be both phronetic and akratic.

In After VirtueAlasdair MacIntyre makes a similar call for a phronetic social science, combined with weighty criticism of attempts by social scientists to emulate natural science. He points out that for every prediction made by a social scientific theory there are usually counter-examples. These derive from the unpredictability of human beings, and the fact that one unpredictable human being can have a world-changing impact. Following Pascal, he argues that the shape of Cleopatra's nose changed the course of history, for if her profile had not been beautiful it is unlikely (according to this argument) that Mark Anthony would have pursued her, with significant consequences for Roman political history.